21st Oct 2021, 4:43 pm | #141 |
Octode
Join Date: Mar 2020
Location: Kitchener, Ontario, Canada
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Re: Commodore PET 2001 voltage regulators
Did you try without UD5 fitted? A bad chip could pull the data bus signals to false levels.
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21st Oct 2021, 5:03 pm | #142 | |
Pentode
Join Date: Oct 2021
Location: Falkirk, Scotland, UK
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Re: Commodore PET 2001 voltage regulators
Quote:
The chip is staying out of the PET as one of the legs has already come off, and there are a couple of others that are a bit wobbly. Tim. |
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21st Oct 2021, 5:12 pm | #143 |
Dekatron
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Location: Newcastle, Tyne and Wear, UK.
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Re: Commodore PET 2001 voltage regulators
Post # 5 of this German forum thread appears to have the binary code content of this PROM, which is a relief, otherwise my mind would have been buzzing over ways to save yours.
https://forum.classic-computing.de/f...power-rom-pac/ You could file into the sides of the chip where the pins came off to reveal a sliver of clean metal to solder to, solder very fine wires (single strands from a piece of multistrand wire) to the metal remains of the missing pins, plug the PROM into a conventional (not turned pin) 24 pin socket and tack solder the other ends of the fine wires to the socket receptacles that the pins would be going to if they were still there. Plug that combination (PROM plus added socket, with its 24 good pins) into your programmer and see if you can read it as a TMS2532 if your programmer supports that device. But anyway... that's an interesting but separate issue to getting the machine working - let's let Tim get his scope, by which time he should also have the test PROMs, and we will be able to get going on this. |
21st Oct 2021, 5:31 pm | #144 |
Octode
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Re: Commodore PET 2001 voltage regulators
I'd certainly be interested in a dump of that ROM.
Tim: What was the link to the information you found? Was there a ROM image there? |
21st Oct 2021, 5:37 pm | #145 | |
Dekatron
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Re: Commodore PET 2001 voltage regulators
Quote:
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21st Oct 2021, 5:38 pm | #146 | |
Pentode
Join Date: Oct 2021
Location: Falkirk, Scotland, UK
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Re: Commodore PET 2001 voltage regulators
Quote:
Hi. The link I found is below: https://datassette.nyc3.cdn.digitalo...it_for_pet.pdf It was just a PDF of the toolkit manual. Tim. |
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21st Oct 2021, 5:40 pm | #147 |
Dekatron
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Re: Commodore PET 2001 voltage regulators
Another source for the manual in various forms here:-
https://archive.org/details/The_Basi...oolkit_for_PET |
21st Oct 2021, 5:43 pm | #148 |
Octode
Join Date: Apr 2018
Location: Newbury, Berkshire, UK.
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Re: Commodore PET 2001 voltage regulators
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21st Oct 2021, 5:56 pm | #149 |
Dekatron
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Re: Commodore PET 2001 voltage regulators
Try installing it in VICE (Commodore emulator program) - see what it does?
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21st Oct 2021, 5:58 pm | #150 |
Octode
Join Date: Apr 2018
Location: Newbury, Berkshire, UK.
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Re: Commodore PET 2001 voltage regulators
Yeh I was going to.... To download it you have to join the forum, I tried that and to join you have to click a link in the verification email which hasn't arrived yet! I'm sure it will someday....
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21st Oct 2021, 6:14 pm | #151 | |
Dekatron
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Re: Commodore PET 2001 voltage regulators
OK, go to the 'other firmware' section of the zimmerman site:-
http://www.zimmers.net/anonftp/pub/c...her/index.html ..and look for these two files Quote:
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21st Oct 2021, 7:13 pm | #152 |
Octode
Join Date: Apr 2018
Location: Newbury, Berkshire, UK.
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Re: Commodore PET 2001 voltage regulators
Yes, that seems to be the ROM that TIM has because of the copyright message when you activate it.
https://youtu.be/VliXpd-bu8s |
21st Oct 2021, 7:17 pm | #153 |
Dekatron
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Re: Commodore PET 2001 voltage regulators
Good, so if Tim eventually wants to get that additional functionality back he can have that code programmed into a TMS2532 to go into the UD5 position.
Some of what it adds in are things we would consider 'standard' for slightly later BASICs, like Auto line numbering and line renumbering. Well worth putting back in eventually. The machine will need to work first, though. |
21st Oct 2021, 7:19 pm | #154 | |
Pentode
Join Date: Oct 2021
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Re: Commodore PET 2001 voltage regulators
Quote:
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21st Oct 2021, 7:25 pm | #155 |
Dekatron
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Re: Commodore PET 2001 voltage regulators
Do that, but be aware that your programmer needs to have the specific ability to read Texas Instruments TMS2532s (not 2732s, which have a slightly different pinout). You could do it with a programmer which can read 2732s, but only if you make an adaptor to rearrange the wiring of pin 18 / pin 21.
If you can actually directly read TMS2532s then please also read the contents of UD6 through to UD9 and save their code as appropriately named .bin files. Last edited by SiriusHardware; 21st Oct 2021 at 7:41 pm. |
21st Oct 2021, 10:16 pm | #156 | |
Pentode
Join Date: Oct 2021
Location: Falkirk, Scotland, UK
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Re: Commodore PET 2001 voltage regulators
Quote:
So I built the adapter (not the prettiest), checking all continuity between between the pins; all, again, was fine. When using the programmer, and setting it to read using a TMS2732A as the template, it passes the tests, but just returns FF for every address, with no ASCII text. So it looks like there could be an issue with the adapter (although all the pins in the continuity test are correct), the programmer just doesn't want to read it, or there is an issue with the chip (with it being initially corroded and the leg falling off - plus a couple of the other legs are wobbly). I'll have a look over it again tomorrow, but thought I'd let you know. At the very worse, it looks like a new EPROM can be programmed with the image file found previously, but it could also be worth testing the chip/socket (to see if the leg fix worked) when the PET is finally running again. |
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21st Oct 2021, 10:17 pm | #157 |
Pentode
Join Date: Oct 2021
Location: Falkirk, Scotland, UK
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Re: Commodore PET 2001 voltage regulators
I suppose I could always just remove one of the other chips from UD6 - UD9 and see if they can be read. Didn't think of that at the time.
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21st Oct 2021, 10:20 pm | #158 |
Dekatron
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Re: Commodore PET 2001 voltage regulators
If you want to have a go, here is how to connect a 2332 PROM to your EPROM programmer so it can be read as if it is a 2732. The easiest way to make such an adaptor is to stack two or more IC sockets one on top of the other, break the connections between PROM pin 18 / reader pin 18 and PROM pin 21 / reader pin 21 as they pass down through the stack, re-route PROM pin 18 to reader pin 21 and re-route PROM pin 21 to reader pin 24 - but, leave the connection between PROM pin 24 and reader pin 24 intact.
If you do this take extreme care to put the PROM in the adaptor and the adaptor in the reader the right way around and do not inadvertently invoke the programming mode of the reader / programmer as it will seriously damage the PROM. Edit: Tim built an adaptor in less time than it took me to describe it The wiring in mine is simpler because it is only for READING, which is the only thing you can actually do with a PROM (the programming in them was fixed at the factory). Last edited by SiriusHardware; 21st Oct 2021 at 10:27 pm. |
21st Oct 2021, 10:27 pm | #159 | |
Pentode
Join Date: Oct 2021
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Re: Commodore PET 2001 voltage regulators
Quote:
Last edited by retromit; 21st Oct 2021 at 10:39 pm. |
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21st Oct 2021, 10:44 pm | #160 |
Dekatron
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Re: Commodore PET 2001 voltage regulators
The TMS2532 is the EPROM equivalent of the non-reprogrammable 2332 PROM, so in read mode they should both look exactly the same to the reader.
It sounds to me as though the adaptor you have made is to 'rewire' a TMS2532 so that it can be programmed with a TMS2732 programmer as well as read with one. (My adaptor only allows for reading). |